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Thiamine (Vitamin B1) Benefits, Side Effects, Uses & Warnings

Thiamine (Vitamin B1) Benefits, Side Effects, Uses & Warnings
Dr. Constance Odom, MD Picture of Dr. Constance Odom, MD

Medically reviewed by

Written by our editorial team.

Last Edited 6 min read

Vitamin B1, often referred to as Thiamine, is a water-soluble vitamin, which is found in many foods including yeast, grains, nuts, cereal, beans, and meat. With this being said, many people suffer from deficiencies of this, and other B-vitamins, due to malnutrition, dietary restrictions (Vegan, vegetarian, etc.), or general health-related immune-deficiencies they suffer from. Because of this, many people supplement Thiamine, and other B-vitamins, to compensate for such deficiencies. Here we’ll detail uses, benefits, how it should be used, what type of supplements work best, and in what dosage, to ensure the best overall results for users.

What does Thiamine do in the body?

What exactly is thiamine’s function in the body? Vitamin B1, or thiamine, helps the body’s cells change carbohydrates into an energy form. Carbohydrates are mainly used by the body to provide energy/fuel when consumed. This is especially true for the brain and nervous system. If the carbohydrates aren’t properly produced, they will not provide the body the much-needed source of fuel, and carbohydrates will simply remain a sugar-form in the body. Thiamine helps with the absorption and processing of complex carbohydrates through the body. Not only to ensure the body has sufficient fuel/energy, but also to ensure it is not improperly stored in the body.

Thiamine is also essential for the metabolism and metabolic functions. It helps the body process foods, it helps your body burn fat/calories during the course of the day and ensures proper functioning of the metabolic system. A deficiency might lead to individuals gaining weight, or possibly having a hard time losing weight or maintaining weight, even if they are on a healthy diet. For this reason, it is important to ensure deficiencies are not only treated properly, and at the proper dosage levels, but are treated in a timely fashion as well.

The sooner a deficiency is spotted, and the sooner supplements are introduced to the body, the easier it is for your metabolism to function, for the body to process food into energy, and to ensure optimal function of the internal mechanism of your body.

What is Thiamine used for?

Most people who take thiamine supplements do so for a deficiency because they don’t receive a sufficient level of thiamine through their diet alone. Others also take the supplement if they are deficient in other B-vitamins, to compensate for such deficiencies. Other uses of the water-soluble vitamin include:

  1. Beriberi and inflammation of the nerves.
  2. Inflammation stemming from pregnancy or pellagra.
  3. Digestive issues including poor appetite, ulcerative colitis, and ongoing diarrhea.

Thiamine is also frequently used by AIDS sufferers, as it helps boost the immune system, and for those who are always suck, or have a weak immune system, the supplementation of thiamine can be highly beneficial.

Individuals who suffer from heart disease, vision problems, canker sores, alcoholism, aging, glaucoma/cataracts, motion sickness, and even cerebellar syndrome, have been prescribe Vitamin B1 to treat such conditions. Prevention of kidney disease in patients with Type II diabetes is another common use for Vitamin B1, and often prescribed by specialists who treat this condition in patients.

Memory loss & Retention issues

Specialists have been known to give patients suffering from memory loss, Alzheimer’s, or enhanced learning disabilities, shots or supplements of Vitamin B1. It not only helps improve memory retention but can also help hinder further memory loss in some patients.

Thiamine has also been used to help with anti-aging and skin conditions in the form of a supplement, ointment, or shots. And, it can help fight stress and increase energy levels, in many people who suffer from fatigue or tiredness.

Because it is a water-soluble vitamin, there isn’t much of a risk of overdose or major complications when using thiamine. It is important however, to discuss use with a specialist prior to starting a dosage cycle. Not only to ensure proper dosage is used, but also to ensure it is properly administered. And, for patients who take other supplements, or prescriptions, your doctor will be the best person to inform you if it is safe to incorporate high doses of Vitamin B1 in conjunction with other medications/supplements you are taking.

Is Vitamin B1 Effective?

Several studies indicate that using thiamine is more effective in treating certain conditions, diseases, or deficiencies, than others. For example, it is highly effective at treating metabolic disorders. Taking the supplement by mouth can help correct inherited metabolic disorders including Leigh’s disease and others.

For those treating a thiamine deficiency, a supplement is also highly effective, and may truly be the only way to cure a deficiency if you have a limited diet. When treating a brain disorder, thiamine has been shown to greatly decrease risk/symptoms of specific disorders, especially those which are specifically linked to deficiencies in the B-vitamin.

It isn’t as effective in treating other conditions. It is possibly effective in treating conditions such as cataracts and vision problems, kidney disease in people who suffer from Type II diabetes, and painful menstruation/cramps for females.

In terms of conditions such as aging, alcoholism, treating AIDS and immune deficiencies, chronic diarrhea, poor appetite and stomach problems (among others), there is limited research, meaning it isn’t clear how effective the supplement is.

Safety Concerns & Possible Side Effects?

Many people who take Vitamin B1 and other supplements, may wonder if there are risks/complications, or side effects they should worry about when taking these supplements. As with any other medication or prescription, you should first discuss use with your doctor, to ensure it is safe and won’t adversely interfere or react with other medications you are taking. Your doctor will best inform you of the possible complications or side effects, based on the other medications and prescriptions being used.

When taken in the form of an oral supplement, Vitamin B1 is likely safe to consume when taken at the appropriate amounts. It is important to note, that although rare, skin reactions, or allergic reactions, may occur in some individuals. When given in the form of a shot, or IV, as long as it is taken at appropriate dosage levels, it is also likely safe for nearly anyone who suffers from a deficiency to take the thiamine supplement. These shots should be administered by a licensed professional or specialist, to ensure they are FDA approved, and are the highest-dosage of the supplement form available.

For those who have liver problems or drink a lot of alcohol, the supplement might not properly enter the body. This might result in insufficient levels of the vitamin being consumed, and possible risk of deficiency still being a problem for some users.

Precautions when taking Vitamin B1

Like all supplements and vitamins, it is important to note some restrictions for use with Thiamine supplements.

  • Women who are pregnant or nursing: it is recommended that no more than 1.4 mg be taken daily during this period.
  • Alcoholism/Liver disease: It is important to note nerve pain can become worsened in individuals who suffer these conditions and take the supplement.
  • Critical illness: if you are critically ill, or have recently had surgery, a thiamine deficiency may exist. Before supplementing, it is best to discuss with the surgeon/specialist.

Those who are undergoing Hemodialysis or suffer from syndromes which make it difficult for the body to absorb nutrients may also suffer from Vitamin B1 deficiencies and may possibly benefit from supplementation. Prior to beginning a dosage cycle, it is important to discuss proper use, and dosing, with your doctor.

There are no known interactions which might adversely affect your health if you are taking Vitamin B1 supplements; however, your doctor is the best indicator to inform you of safety, possible complications, and other health-related risks or concerns you should be aware of, prior to beginning to use the supplement.

Possible food interactions

Tannins, which are found in coffee and tea, might possible interact with thiamine. This can make it develop into a form which is harder for the body to ingest, leading to a deficiency in the vitamin. Seafood, namely in the form of freshwater fish and shellfish, can also lead to destruction of thiamine. Consuming cooked fish shouldn’t cause such problems. If you consume raw fish in high quantities, a deficiency might present itself, for which a supplement will benefit users.

How much B1 should you take?

When taking thiamine, as well as other B-vitamins, supplements, or any other medication for that matter, proper dosage levels should be taken, to ensure safety and optimal ingestion results. Consider the following levels:

  • For adults, by mouth, 5-30 mg daily is sufficient in treating deficiencies. It is recommended not to exceed 300 mg daily.
  • When treating metabolic disorders, recommended dosage is between 600 to 4000 mg daily.
  • Reducing the risk of getting cataracts, the recommended dosage is 10 mg daily.
  • For treating kidney disease in Diabetes Type II sufferers, recommended dosage is 100 mg taken 3-times daily.

When supplementing via injection, for treating symptoms such as alcohol withdrawal symptoms, many healthcare professionals may give up to 2 shots, of 5-200 mg daily. This will vary with each patients, deficiency, and types of conditions being treated.

Do you have to treat a deficiency?

A Vitamin B1 deficiency can prove detrimental to many. Some of the issues you’ll notice if you are deficient include:

  • Lack of energy/drive to do anything.
  • Possible weight gain or difficulty maintaining weight (due to metabolic imbalance).
  • Difficulties treating certain conditions, metabolic/dietary.
  • Malnutrition which stems from poor diet, and vitamin-deficiencies.

Of course, no two cases are alike. One person might be deficient and function normally while the next finds it hard to remember things, or get through the day, if they suffer from a thiamine deficiency. In most cases, it isn’t a life-death issue, where not supplementing can cause major health concerns, but overtime, it can lead to health concerns, issues, and can possibly interfere with other essential vitamins/minerals in the body.

So, if a deficiency is noted, it is best to speak to your doctor immediately, to determine the best approach in treating it, and finding the proper dosage level, based on the level of deficiency which you suffer from. Only a specialist can properly inform you of the right dosage levels, based on your deficiencies, and based upon your medical history (and other medications and prescriptions you take). The sooner the deficiency is realized, the easier it is to treat, and avoid further/future deficiencies with other essential B-vitamins in the body.

Vitamin B1, or thiamine, serves many purposes in the human body. Its main functions are to help with general metabolic processes. This can extend from helping the body process foods, turn sugar/carbs into fuel and energy, help boost the rate at which your metabolism functions, to helping you maintain a healthy weight. The vitamin is also essential in helping the body breakdown the carbohydrates which are consumed, to ensure you have sufficient fuel and energy sources, to get through the day. Not all individuals get sufficient levels of Vitamin B1 through their diet alone. And, even those who consume foods which are high in the vitamin, tend to suffer from minor deficiencies, which a supplement can easily treat.

These are just a few of the basics one should familiarize themselves with, if they notice any of these symptoms, lack of energy, or suffer from memory loss conditions (especially those linked to vitamin deficiencies). Not only is it simple to properly diagnose the issues, and find the right treatment, but the sooner it is treated, the easier it is to not only treat the deficiency, but also hinder or eliminate the possibility of other deficiencies developing at a later date.

Whether you suffer from a deficiency, or simply want to learn how to properly incorporate a thiamine supplement into your diet, there are several factors to consider prior to starting a dosage cycle of Vitamin B1, and other vitamins or supplements. This is a simple guide to help you determine if you require a supplement, should speak to a doctor, or should look for alternative approaches in treating a deficiency, based upon other health risk/concerns, or possible interactions with other medications or prescriptions you are currently taking.

This article is for informational purposes only and does not constitute medical advice. The information contained herein is not a substitute for and should never be relied upon for professional medical advice. Always talk to your physician about the risks and benefits of any treatment. Nu Image Medical may not offer the medications or services mentioned in this article.